The corn stover should be stored under the conditions of keeping its normal amount of moisture against rain and soaking from the ground, avoiding decay and ensuring protection against fire. The selection of a storage type will depend on location and local conditions. The corn stover can be stored in open storage, tarped storage, permanent structure storage or anaerobic storage[1]. Several factors should be considered when selecting appropriate storage systems: feedstock stability during storage, cost of storage infrastructure, accessibility of feedstock during the entire storage duration, integration of storage platform with processing plant.

The storage of biomass in permanent structures offers many advantages in comparison with other systems. However, due to relatively low density of corn stover, including bales, and high capital costs for new storages building the permanent storages are economically unfeasible. In the case, if stakeholder has permanent storages he can use them for corn stover.

The large square bales tarped storage costs are 3.1 EUR/ t d.m., which are lower than storage costs of round bales (5.0 EUR/t d.m.) and shredded corn stover (6.9 EUR/t d.m.).

Prepared by: Semen Drahniev – Member of the Expert Council of the Bioenergy Association of Ukraine for the platform of sustainable agribusiness SAF Ukraine.

Corn residues storage costs. Semen Drahniev. The platform of sustainable agribusiness SAF Ukraine. November 04, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.

The economic feasibility of corn residues harvesting depends on capital (key element) and operating costs.

Capital expenditure is the cost of purchasing equipment. Operating costs are the costs of fuel, amortization, maintenance and repair, materials and labor.  Operating costs considerably depends on machinery productivity and the distance of transportation of bales from the field to the central storage facility.

According to the corn stover harvesting cost estimation results, the net cost of collected biomass on the storage facility can be from 22.3 EUR/t d.m. Following storage and densification in briquettes or pellets will increase the added value of the corn stovers.

Prepared by: Semen Drahniev – Member of the Expert Council of the Bioenergy Association of Ukraine for the platform of sustainable agribusiness SAF Ukraine.

Cost of equipment and operations related to harvesting of corn residues. Semen Drahniev. The platform of sustainable agribusiness SAF Ukraine. October 23, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.

In addition to the technologies for harvesting corn residues in bales described in the previous article, this biomass can be also:

  • pressed into rolls using a roll baler instead of a baler of rectangular bales;
  • collected in a crushed form as a mixture of different fractions of plant residues;
  • collected in a crushed form in a separate fraction of plant residues, such as rods.

Prepared by: Semen Drahniev – Member of the Expert Council of the Bioenergy Association of Ukraine for the platform of sustainable agribusiness SAF Ukraine.

Technologies for harvesting corn and corn residues (in bales). Semen Drahniev. The platform of sustainable agribusiness SAF Ukraine. October 15th, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.

There are several technological schemes for harvesting grain corn. Currently, the main method for harvesting commercial corn is combine threshing of ears in the field, shredding and spreading of the cut biomass with the use of combine harvesters equipped with corn reapers. This method of harvesting grain corn is the most economically feasible. In comparison with harvesting ears, the method provides 1.8-2 times decrease in labor costs and 20-25% reduction in fuel consumption[2]. Only a few agricultural enterprises (seed factories) collect corn as non-threshed ears with the following stationary threshing, which makes it possible to collect cobs. The seed factories grow corn to obtain (hybrid) corn seeds as planting stock. Collection of mixture of grain and cobs with combines is not widespread in Ukraine yet.

For Ukraine, we recommend “combine + tractor with stalk-shredding windrower + tractor with baler” technology.

Prepared by: Semen Drahniev – Member of the Expert Council of the Bioenergy Association of Ukraine for the platform of sustainable agribusiness SAF Ukraine.

Technologies for harvesting corn and corn residues (in bales). Semen Drahniev. The platform of sustainable agribusiness SAF Ukraine. October 8th, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.

Сorn residues have quite good fuel properties which are close to those of wood fuel. Due to that, biofuels made from corn residues can be burnt in the equipment intended for wood biomass.

  • Ash content of corn stover is a major quality factor for further production of biofuels. The ash content depends on the type of harvesting technology as the amount of ash increases when biomass is contacting with soil. Typical total ash content for multiple passes of agricultural machines when harvesting is 8-10%.
  • As regards ash melting behaviour, corn straw is close to wood biomass, which provides better conditions for combustion compared to straw of cereal crops.
  • Corn straw contains less chlorine (0.2% d.m.) compared with fresh ("yellow") straw of spiked cereal crops (0.75% d.m.). This is a positive factor for corn residues as fuel as chlorine compounds cause corrosion of steel elements of energy equipment.
  • The elemental composition of corn straw is almost the same as that of straw of spiked cereal crops, so they have a comparable calorific value.
  • The properties of straw strongly depend on the place of cultivation, harvesting time and weather, soil and fertilizers.
  • The biggest effect on the calorific value of corn residues is produced by their moisture content

Prepared by: Semen Drahniev – Member of the Expert Council of the Bioenergy Association of Ukraine and Tetiana Zheliezna – Member of Auditing Committee for the platform of sustainable agribusiness SAF Ukraine.

Fuel characteristics and properties of corn residues. Semen Drahniev, Tetiana Zheliezna. The platform of sustainable agribusiness SAF Ukraine. September 18, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.

Assessment of the corn residues potential for energy in 2018 based on the approach developed by the Bioenergy Association of Ukraine shows the following results:

  • the theoretic potential (the whole amount of residues generated) is 46.5 Mt or 8.9 Mtoe;
  • the economic potential (the amount available for energy that is 40% of the theoretical potential) is 6 Mt or 3.6 Mtoe including stalks – 9.7 Mt (1.9 Mtoe) and cobs – 3.3 Mt (0.6 Mtoe).

Distribution of the corn residues potential over Ukraine’s territory is not even. Regions with the highest concentration of this type of biomass are oblasts with the biggest production volumes of grain corn. For 2018, they are Poltava oblast (with the economic potential of corn residues 489.6 ktoe in 2018), Chernihiv oblast (382.2 ktoe in 2018) and Vinnytsia oblast (372.2 ktoe in 2018).

Prepared by: Semen Drahniev – Member of the Expert Council of the Bioenergy Association of Ukraine and Tetiana Zheliezna – Member of Auditing Committee for the platform of sustainable agribusiness SAF Ukraine.

Potential of corn residues in Ukraine in 2018. Semen Drahniev, Tetiana Zheliezna. The platform of sustainable agribusiness SAF Ukraine. September 04, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.

Residues of grain corn production consist of:

  • stalks which make up about 52.5% of the whole mass of the residues. At that, the stalk makes up 27.3% of the mass of the whole plant including grain (the same indexes are presented below for other parts of corn residues);
  • leaves – 20.0 % (10.6%);
  • cobs – 17.5% (9.0%);
  • wrap of ear – 8.5% (4.3%);
  • other parts – 1.5% (0.8%).

Production of agricultural residues, including corn residues, is seasonable and depends on harvesting periods. Grain corn is harvested during different time frames, depending on the variety, the place of cultivation and the time of sowing. Usually, time frame for harvesting corn is determined by the level of grain moisture, so before harvesting, they determine the moisture content of the grain and its ripeness, taking into account the terms of sowing and the hybrid ripeness group. By the beginning of harvesting, the corn grain must have a high dry matter content (at least 45%).

Prepared by: Semen Drahniev – Member of the Expert Council of the Bioenergy Association of Ukraine and Tetiana Zheliezna – Member of Auditing Committee for the platform of sustainable agribusiness SAF Ukraine.

Residues of grain corn production and its harvesting periods in Ukraine. Semen Drahniev, Tetiana Zheliezna. The platform of sustainable agribusiness SAF Ukraine. August 28, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.

Corn is the most high-yield crop, all the parts of which are widely used in different industries for many purposes, in particular:

  • for food production;
  • as feedstock in pharmaceutical, chemical and other branches of industry;
  • as high-energy fodder that is suitable for all kinds of animals and birds;
  • as raw material for the production of first and second-generation biofuels;
  • as raw material for the production of biogas.

Corn is a crop of high agro-technological value as it cleans soil of weeds and is a good precursor in the crop rotation. Judging by the absorption of carbon dioxide and release of oxygen, corn is one of the best crops and is even more effective than a forest of the same area.

The USA is the world leader in corn production and yields. According to some preliminary data, the production of corn in the USA in 2017/2018 MY was 371.1 Mt (34.5% of the global production), the average yield was 11.1 t/ha. In other countries, the production of corn in 2017/2018 MY was the following: China – about 259 Mt, Brazil – 82 Mt, the EU – 62 Mt, Argentina – 32 Mt, India – 29 Mt, Mexico – 27.5 Mt and Ukraine – 24 Mt (the 7th place in the world). At that, the USDA forecast for Ukraine for 2018/2019 MY is 35.5 Mt, which can bring the country to the 5th place.

Prepared by: Semen Drahniev, Member of the Expert Council of the Bioenergy Association of Ukraine, for the platform of sustainable agribusiness SAF Ukraine.

State of the art of corn production in the world and in Ukraine. Semen Drahniev, The platform of sustainable agribusiness SAF Ukraine. August 21, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.

The development of biomethane production is the result of political will and reliable, long-lasting financial support mechanisms and investment subsidies, as biomethane cannot compete with natural gas in today's market conditions. Many European countries have already established mechanisms to support biomethane.
Different countries use different support mechanisms to develop biomethane technologies. These mechanisms operate at different points in the biomethane value chain.

Germany and Sweden were the pioneers in this area. Germany actively used, from 2000 to 2014, a green tariff for electricity from biogas, additional bonuses for enriching biogas to the quality of natural gas and the use of energy crops (corn silage). From the very beginning, Sweden encouraged the use of biomethane as a motor fuel and exempt use of biomethane from carbon and energy taxes.

In recent years, biomethane production has been actively developing in France, Italy, Denmark, the United Kingdom and the Netherlands.

National support schemes include measures such as Feed-in-Tariffs (FIT) for produced biomethane or produced electricity from biomethane, investment support, quota systems or tax incentives. In addition to financial support, there are incentives in licensing and legal aspects to reduce project risks.

Mechanisms for supporting biomethane production and consumption. Yurij Matveev. The platform of sustainable agribusiness SAF Ukraine. August 15, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.

Electricity produced from biomethane can already today be supplied to the grid at a “green” tariff of 0.1239 €/kWh (excluding VAT).

However, the idea of ​​enriching biogas to biomethane is precisely the possibility of pumping it into the natural gas (NG) network.

To create conditions for the use of biomethane from the NG network in the combined production of electricity and heat, it is necessary to create a national register of biomethane with the possibility of issuing certificates of origin, such as European certificates GoO (Guarantee of Origin). In the long term, with such a certificate, virtual trading of biomethane with EU countries is possible.

After the introduction of the biomethane certification system, a gas power plant with the intention of using biomethane can be connected to any location where there is a NG network and a heat consumer (eg boiler, CHP).

Economic prerequisites for the production and use of biomethane in electricity/heat production in Ukraine. Petro Kucheruk. The platform of sustainable agribusiness SAF Ukraine. July 26, 2019.

The Bioenergy Association of Ukraine since 2019 is a partner of the platform of sustainable agribusiness SAF Ukraine.