How to make ethanol cheaper

Биоэтанол

One of the reasons that hinders a widespread use of ethanol fuel (bioethanol) in the energy sector is the relatively high cost of its production. Currently, to produce fuel ethanol in Ukraine, there is used principally the same technology as for the production of edible ethyl alcohol. The cost price of such ethanol is about 7 UAH per liter, which requires a reduction of the tax pressure on ethanol-containing fuel, and this is a loss for the budget. The solution consists in decreasing the cost of bioethanol at the expense of creating and implementing new production technologies that will reduce the cost of raw materials by 50 … 60% and energy consumption by 60%.

We offer basic technological solutions that allow to achieve these results.

The cheapest raw material for the production of bioethanol is considered to be corn. Only corn starch is converted into ethanol, and the other components – fat and protein are the ballast. Fat slows down technological processes of saccharification and fermentation, excessive protein increases the viscosity of intermediates, creating deposits on the inner surfaces of mash columns and heat exchangers, which leads to increased consumption of enzyme preparations and process steam.

The corn grain contains 10 … 14% of the germ by weight, which comprises 84 … 86% of fat, and 25 … 30% of corn protein. Corn germ is used to produce corn oil, as well as a variety of fodder and food products.

It is necessary to implement the technology of preliminary separation of corn grain into germ and cereal starch. The main type of equipment for that is degerminator – a special crusher, which crushes grain and separates the germ from the endosperm at the same time. Polydispersed cereal starch goes to the production of ethanol, and the germ is used for the production of commercial products – oil, protein paste etc., implementation of which can significantly reduce the cost of bioethanol. Part of defatted starch cereal can be realized to beer producers, or can be used for production of wide range of other food products – from chips to molasses.

World experience and calculations that were made considering the conditions of local market allow us to state that the total value of the commodity products derived from the selected germ compensates up to 80% of the cost of raw materials for the production of bioethanol.

Corn grits and flour, extracted from the germ by the method of determination contain 75 … 80% of starch and about 5% of protein. Studies carried out at the Institute of Food Chemistry and Technology have established that the use products mentioned wort allow to obtain the high concentration of solids and thus increase the strength of the mash. By using the new enzyme preparations, phytase in particular, yield of bioethanol from the raw material can be increased, and by reducing the viscosity of the mix, costs of liquefying and saccharifying enzymes can be reduced by 10 … 20% and mash maturation is reduced to 40 … 48 hours, thus ethanol yield is increased by 0.5% and the power consumption is reduced by 5 … 8%.

The electricity consumption for germ selection and crushing of the grain starch component approximately corresponds to the costs of its raw material crushing using conventional technology.

Therefore, germ separation special line introduction in the raw material processing flow chart will compensate up to 85% of purchased raw materials price due to the implementation of further obtained products.

Raw material costs make up 50 … 60% of the bioethanol cost price structure. Even at a conservative estimate, manufacturing cost price of bioethanol can be reduced by 20 … 30% through the introduction of technology.

Institute of Food Chemistry and Technology proposed an implementation of the project of corn grain complex processing production line. The cost of a technological equipment set for corn processing with an output of 100 tons per day is about 350 thousand euros, and the payback period for the corn preparation plant and degerminators is about 5 … 8 months.

Another important factor which affects bioethanol cost price is the cost of thermal energy for its production. Before natural gas prices increase, thermal energy was approximately 20% of the cost price structure. At the present time its level increased up to 25 … 30%. Expenses of process steam for the production of a decalitre of bioethanol amounts 60 … 70 kg. These energy costs are caused mainly by irrational design of rectification process flow diagram of bioethanol rectification and dehydration.

Rectification devices are traditionally created in the alcohol industry to implement the technology, the essence of which was to obtain highly purified food grade ethanol, and the level of incurred energy losses was not decisive at the time. Taking into account the quality requirements of bioethanol, production emphasis must be shifted on minimizing energy consumption because limiting the content of accompanying volatile impurities in bioethanol essentially has no effect on conditions for its use as a fuel.

Our research and calculations have shown that steam costs can be reduced threefold in case of rational technological solutions implementation at the stage of dehydration and rectification. Figure 1 shows a schematic flow diagram of the installation for bioethanol production from the mash, which allows to achieve such level of performance. Heating steam for rectification enters only mash column, allowing 2.5 times costs decrease. Steam costs are reduced up to 20 … 22 kg per decalitre of bioethanol provided the use of other energy saving technology solutions, including the use of secondary heat. Mentioned circuit elements are tested in a production environment.

The advantages of such a scheme are the impossibility of obtaining food grade ethanol in it, which completely eliminates the possibility of improper use of ethanol-containing products, necessity of excise control and related complications during its production and alternative fuels trafficking on the market.

Implementation of the aforementioned scheme requires new distillation columns and heat exchange equipment design because the equipment used until then at distilleries in Ukraine for food alcohol production is not able to provide new technological requirements for bioethanol production in the amount advanced by energy-saving solutions.

Implementation of energy-saving production schemes together with the proposed scheme of complex raw materials preparation makes it possible to reduce production costs up to 1.5 … 2 UAH. per liter, which will provide high level of competitiveness in the fuel market to the alternative fuel.

In order to implement energy-efficient technologies for producing bioethanol competitive with petroleum-based fuels in the domestic market, as well as with similar bioethanol in the foreign market, significant investments for existing distilleries redevelopment are necessary.

Let us recall that at the moment the total potential capacity of all distilleries in Ukraine amounts 600 thousand tons per year. The need for Ukraine in excisable alcohol (food, perfume, etc.) is 150 … 200 thousand tons and the domestic market of fuel bioethanol can achieve at least 800 … 1200 more thousand tons per year. Existing market demand for bioethanol (including global) allows a quick increase of its production capacity in Ukraine. The EU countries are interested in importing ukrainian fuel bioethanol. European bioethanol market annually increases by 3% indicating a significant potential for domestic exports. There is a potential for raw materials production (primarily corn) in Ukraine.

Further expansion of production (including for export) should be carried out by increasing the processing of corn and other crops, providing a stable commodity market for agricultural producers and the establishment of multidisciplinary regional agro-industrial complexes. This will stimulate the organization of renewable raw materials production in the Ukrainian agricultural sector, its complex processing into biofuel and fuel components, food products, fodder and other products, which will ensure the sustainable development of their location territories.

Being provided with modern energy-saving production scheme, large sized territorial raw processing complex built on the basis of bioethanol plant is capable to process 250.0 thousand tons of raw grain per year. There must be 50 … 80 thousand hectares of farmland to cultivate the grain. These areas will be fertilized with their own organic-mineral fertilizers, and the processing will be provided by their own fuel.

Animal husbandry development in the contiguous zone will be provided with its own mixed fodder and succulent fodder due to crop rotation.

The creation of such systems will have a significant social impact through increased employment of population. Besides mentioned, stable sales of crop production will be provided. Agricultural producers will get a cheap fuel and fertilizer produced locally. Complexes of such capacity are already operating in the US and Canada. They also are being built in Germany, Russia and Kazakhstan.

Currently, Ukraine is possible to start with relatively small territorial raw processing plants based on repurposed distilleries, designed for annual processing of 25 … 30 thousand tons of corn and 10 … 15 thousand tons of rapeseed. The essential feature of biodiesel production is the use of own bioethanol for the transesterification instead of purchased methanol, which is produced from fossil raw materials. Creating a multidisciplinary agro-industrial complexes for processing corn into bioethanol is an immediate prospect for Ukraine.

 

S.Tsygankov, Ph.D.

Яндекс.Метрика