[for reference: Doctorate in Philosophy]

The Synthesis and Use of Biodiesel

Thesis Abstract

Industries structured around large scale production and large scale waste, making use mostly of fossil fuels, underpinned our lifestyles in the 20^th century, and this serious misapprehension about what constitutes “riches” demands that we reconsider our lives and behave differently.

In the current paper, the recycling of used cooking oil is seen to enable the regional creation of a sustainable society and of an industry in harmony with its environment.  This suggests a possible direction for regional industry and regional society in the current century.

Set against this background, the paper has the following threefold aims:

(1)   To elucidate the lubricating properties of biodiesel.

In this context, the lubricating characteristics of biodiesel when used as an additive to diesel fuel and kerosene are investigated, and the usefulness of biodiesel is demonstrated as an additive to improve lubricity.

(2)   To search for a solid catalyst for synthesizing biodiesel and glycerin from fat/oil and methanol and to discuss the influence of the reaction conditions on the yield and selectivity of these reaction products. 

Here, focusing on a solid‑base catalyst, a heterogeneous catalyst is prepared to replace the homogeneous catalyst, and its catalytic properties are demonstrated.

(3)   To investigate the practical value of biodiesel, both as a diesel fuel and as a lubricating additive to fuels.

Here, from an economic and environmental perspective, the practical potential of biodiesel is more deeply probed, both as a fuel for diesel engines and as a lubricating additive.

In chapter 1, the introduction, the research to date on the properties of biodiesel as a fuel and on its production process is summarized, and within this context, the aims of the current paper are set out.

Chapter 2 discusses the various uses of biodiesel: as a fuel (100% biodiesel); for mixing with diesel fuel and kerosene; and for adding to diesel fuel and kerosene to improve their lubricity.  Taking into account quantitative constraints, it is pointed out that we should focus on turning biodiesel into the product that offers the greatest possible value-added (a lubricity-improving additive).  In particular, based on the lubricating effects of biodiesel, its effectiveness as a lubricity-improving additive to low-sulphur diesel fuel and kerosene is discussed.

Chapter 3, at the same time as solving the problems of disposing of the waste products from the production process and of separating the products from the catalyst, flaws in biodiesel production methods to date, discusses how the use of a solid base catalyst enables us to take advantage of synthesizing techniques for biodiesel and glycerin, moving us towards an increasingly practical plant.  In the traditional production method, the manufacturing process involves a final separation stage in which, in order to get rid of the base, the latter needs to be rinsed with water to neutralize it.  This process not only generates large quantities of a harmful side-product (waste product), it also makes it harder to retrieve the glycerin.  Under today’s environmental regulations, it is even possible for the cost of disposing of the waste product to exceed the value of the biodiesel.  For future biodiesel production, we have reached the point of adopting a clean technology based on a heterogeneous base catalyst process ― in other words, full exploitation of the advantages of heterogeneous base catalysts.  This is because future producers will be able to take advantage of a process that allows continuous flow systems, combining the following two functions: since the separation of the product (biodiesel) is easier, it is possible to re-use the catalyst; and both activation and replacement of the material take place, on the boundary between the catalyst support and the activated phase.  In addition, on the subject of the standardization of biodiesel products and from the standpoint of the observance of product quality laws, it is also stated that, as we aim for biodiesel that is both more reliable and more practical, the time has come for Japan to rapidly establish the appropriate product standards.

Chapter 4, within the current environment of diesel fuels with ultra low sulphur levels, turns to one widely-used test of lubricity, the high frequency reciprocating rig wear (HFRR) test, and its corresponding satisfaction threshold-value.  Within this context, when we take into consideration the preservation of lubricity, various atmospheric conditions, and the severity of sulphur discharges, it is suggested that, to be safe, it is necessary to reduce the current standard of 460 μm (i.e. to impose a lower satisfaction threshold-value for wear scars) and, to back-up the HFRR test, the establishment of a new testing method and standards based on data from actual engine/vehicle tests is proposed.  In addition, as in future the preservation of environmental standards requires increasing social expenditure to cover the rising cost of further reductions in the sulphur level of diesel fuel, and as regional authorities respond to this in various ways, efforts to restore regional economic growth (saisei) will be shunted into new channels.  Combined with engineering solutions making biodiesel more practical (chapter 3), this has the potential to have a significant future impact, bringing new life to communities as sustainable societies.

When, as described in this paper, the value-added of used cooking oil is increased and it is fully consumed within a region, not as a regional waste product but as a material resource, then that oil’s environmental potential is being exploited to the full.  When we consider the important role in the construction of a sustainable society played by the recovery of used cooking oil as a resource, we can see how this also provides a suggestion for how to revitalize the regions.

In place of an ethic of production and resource exploitation, a new regional (social) growth ethic, which involves incorporating the material cycle of regional consumption and waste into the social structure, is the guiding inspiration behind regional development.  We need to look at the total lifecycle of products, and review not only hitherto unused materials but also the cyclical potential of those which may yet generate fresh value-added.  Identifying the new material value locked within the post-use lifecycle of cooking oil and making efficient use of this is what will generate fresh value for the regions.  It is evident that we are moving into an era when the products being used are increasingly those that effectively capitalize on regional resources – products, therefore, to which regions can lay claim.

The fruits of this research allow us to identify potential uses for biodiesel and their new social significance.  As we turn to the future, it is desirable to promote further innovations in the production process from an engineering perspective, and to look toward the construction of a regional industry that generates fresh economic value-added.