Een grote producent van zonnebloemolie heeft de laatste jaren fors geïnvesteerd in nieuwe installaties. In het productieproces is veel energie nodig waarvoor momenteel aardgas wordt gebruikt. Het bedrijf heeft in Roemenië gezien dat Host interessante installaties kan leveren voor energieproductie op basis van het bedrijfsafval. Het Moldavische bedrijf heeft belangstelling voor zo'n installatie. Momenteel beschikt het bedrijf echter niet over voldoende financiële reserves om te investeren.
Een investeringsmaatschappij is hiertoe wel in staat en bereid en wil in de energie-opwekkingseenheid, die op het terrein van de counterpart moet komen, investeren. De counterpart zal op zijn beurt de energie afnemen en zo lagere operationele kosten hebben dan als er op aardgas gestookt wordt. Een studie moet uitwijzen of het project haalbaar is.

De studie is afgerond op 14-06-2006

Summary
Under the authority of Senter, HoSt has done a PESP study in which the feasibility of a project is investigated involving gasification of the husks, steam production in new boilers, electricity production with help of a steam turbine and delivery of steam to the processes at Floarea Soarelui, Moldova.

Floarea Soarelui is the largest production factory of sunflower oil in Moldova. The remaining of processing sunflower seeds are the shells from the seeds, called husks. Like in almost every sunflower oil company, the husks are used as a fuel for steam production by means of combustion technology.

In the present situation the husks are combusted by means of very old boilers. By combustion of the husks by boilers, problems like a relative low boiler efficiency (65 percent), cleaning of the boilers every four weeks, a low availability and reliability and high dust emissions arise. To reduce the problems, the possibilities of a gasification installation based on the usage of the sunflower husks have been investigated.

Therefore the steam consumption, the needed steam pressures and temperatures, oil production, availability of husks for energy conversion, gas consumption and energy tariffs have been inventoried. Also the possible locations have been determined in co-operation with Floarea Soarelui.

Based on the inventoried information, several options for the integration of the gasification installation in the present situation have been developed. After discussions with the management and operators of Floarea Soarelui four options have been chosen for global calculations. The following four options to be build at the factory have been determined:

Option 1:     two gasifiers using half the available husks capacity each, providing steam to a condensing steam turbine;

Option 2:     a gasifier using half the available husks capacity combined with the existing КΕ-boiler using half the available husks capacity, providing steam to a condensing steam turbine;

Option 3:     two gasifiers using half the available husks capacity each, providing steam to a back pressure steam turbine;

Option 4:     a gasifier using half the available husks capacity combined with the existing КΕ-boiler using half the available husks capacity, providing steam to a back pressure steam turbine.

Calculations have been made and the most attractive solution has been chosen in co-operation with Floarea Soarelui. This solution exists of the construction of one new gasifier plant suited for half the capacity of husks. One of the newer existing boilers (КΕ-boiler) will be used in the new concept to combust the other 50 percent of husks available and to deliver the high-pressure steam for the processes. Through this combination a maximum output of electricity is realised and the needed investment is limited. The plant will be equipped with a condensing steam turbine, condensing to a pressure of around 0.2 bara. With this concept around 1,760 kWe of electricity will be produced on average during the year.

The production of heat and electricity is calculated based on the efficiency of the gasifier, steam boiler and turbine. The costs, profits and investment costs of the gasification installation are determined. The costs and profits are based on the present energy tariffs. The investment costs of the gasification installation are determined based on offers of several suppliers. If possible the suppliers are of Moldavian origin.

Floarea Soarelui has to invest in a new or improved energy production. Therefore the extra investment costs of the gasification installation are compared to the investment costs of husk fired boilers producing solely steam.
Based on the extra investment costs of the gasification installation compared to the husk fired boilers, cash flow calculations have been made, resulting in the Internal Rate of Return and pay back time. The pay back time is determined at about 3 years.

The ashes of a gasification plant of HoSt in Romania have been analysed by ECN (a research facility in Petten). The results of the analyses have been sent to the State Agricultural University of Moldova. Based on the results, the university has concluded that the ashes can be used as a fertilizer, especially for potatoes. The possibilities of the usage of the ashes as fertiliser were discussed with the local authorities in Moldova. Up till now, the authorities are not able to give a positive or negative reaction. Two reasons can be given for this. On the one hand, the authorities are unfamiliar with the gasification process and the eventual usage of the ashes. Therefore it takes a lot of time to convince the authorities. On the other hand, Moldovia has a lot of bureaucratic rules. To obtain the permission to use the ashes of the gasification installation, the agricultural department and several other departments have to agree and stamps on official documents are needed. If the gasification plant will be built, the procedure to obtain the permission to use the ashes will be started. The first two years the ash will be disposed. As in the Netherlands, the other possibility is to deliver the ashes to artificial fertiliser producers.

At the moment Floarea is comparing the offer provided by HoSt with the option to buy a second hand Russian steam boiler plant based on combustion.