Supplement Hydrogen Gas To Improve performance of Diesel Engine for Power Generation

ABSTRACT 

The consumption of fuel oil for diesel engine for power generation is quite large, as long as there is no substitute alternative fuel other than oil. With diminishing oil reserves, then there is the possibility of inadequate fuel needs as diesel fuel in the future. One of the options that will most likely become an alternative solution for this problem is hydrogen substitution. Hydrogen production from water through an electrochemical process   that requires heat and chemicals materials was developed. The design of this electrolysis equipment to produce hydrogen gas is important as it will be combined directly to the diesel engines. Hydrogen will be injected into a combustion chamber of a diesel engine resulting in mixing of hydrogen, oxygen and fuel gas in the combustion chamber to improve the combustion efficiency. Preliminary experimental result of hydrogen diesel fuel mixture in order to reduce diesel fuel consumption are reported, as well as a measurement of the exhaust gases such as carbon monoxide (CO), carbon dioxide (CO), sulfur dioxide (SO2) and nitrogen dioxide (NO2) are reported. 
Keywords: Hydrogen, HHO, Emission Gas 

1. INTRODUCTION
Fossil fuel consumsion in various indutries is dominant, therefore need an effort to do conservation in order to reduce it. Domestic oil consumption is higher than the production capacity of oil refinery in the country. The crude oil production increase continuously lead to a situation to force export crude oil and import oil. The prediction of domestic demand in the country in 2010 is about 1.6 million barrel per day, this means the need of 2 million  barrel per day of crude oil[1].
Therefore it is necessary to reduce fuel consumption or even a replacement fuel for diesel consumption. One of the options that will most likely become an alternative energy fuel is hydrogen gas in the future. Hydrogen gas can be produced from various resources (water, fossil fuels, or biomass) or a by product of other chemical processes. Hydrogen production with raw material sources of water through an electrochemical process that is often referred to as the process of electrolysis.  A converter separates water into a gas called hydroxy or HHO (2 hydrogen atoms and 1 oxygen atom). HHO gas is also known as browns gas using the electricity from the battery of the vehicle. A converter produces hydrogen and also retains the stability of water. Once burned as fuel in the vehicle the end product is H2O. It is easy to install affodarable and a quart of water can last for months. HHO is a form of gas created by electrolysis. Ordinary water contains a ton of energy, but the trick is to get that energy out without using a lot of energy to do so. The creation of pure hydrogen gas is impossible. As of now, it is not even economical for large corporations. In general, the process to produce hydrogen gas requires heat energy and chemicals.
Injection system of hydrogen gas to the diesel engine is investigated in this paper  in order to see its possibility to reduce diesel consumption at the same load. This technology has been test in otomotive successfully. Injected hydrogen aids the primary diesel fuel to burn more efficiently and helps trigger the chain branching reactions. Hydrogen (H) is easily burn. Therefore, injected H2 into the combustion chamber will give a huge energy. It would speed up the combustion process and it is assumed might raise the efficiency of the diesel engine[2]. The theoretical thermodynamic efficiency of an combustion internal engine is base on the compression ratio of the engine and the specific-heat ratio of the fuel as shown in the equation:




The higher compression ratio and / or the specific- heat ratio, the higher the indicated thermodynamic efficiency of engine. The specific-heat ratio is related to fuel’s molecular structure. Hydrogen (γ = 1.4)  has a much simpler molecular structure than conventional fuel oil (γ = 1.1) [3]. The combustion of hydrogen with oxygen produces water as its only product:  

2H2+O2= 2HO 

 The combustion of hydrogen with air however can also produces oxides of nitrogen (NOx) 

H2+O2+N2 = N2O+N+NOx 

 The oxide of nitrogen are created due to the high temperatures generated with the combustion chamber during combustion. In additional to oxide of nitrogen, trace of coabon monoxide and carbon dioxide can be present in the exhaust gas[3]. Injection technic and point to inject the hydrogen gas in the combustion chamber of the diesel engine is important to rate the experiment success. Observation to investigate the ability of HHO to mix with oxygen inside the combustion chamber and with the diesel oil that entering the chamber will be monitored. Emission output such as carbon monoxide (CO), carbon dioxide (CO), sulfur oxide (SOx), and nitrogen oxide (NOx) will be monitored. It is assumed that injection of hydrogen gas in the combustion chamber of the diesel engine will raise its efficiency and will reduce diesel oil usage by the same power. This is the hypothesis of this study. 



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2.   EXPERIMENTAL SET-UP

The principle process of water electrolysis is stretching of molecular hydrogen and oxygen in a water  tank   using   Sodium   Hydroxide   catalyst (NaOH)   and   it   charged   with   electricity   from

battery.   The   schematik   process   electrolysis   of water to produced hydrogen gas shown in Figure1.

Figure 1. Schematic diagram concept of hydrogen generation

Hydrogen   is  flowing  to  the  negative  pole  and oxigen  to the positive  pole  of the electrode.  The efficiency will depend on a quality of the materials of electroda  and the quality of electricity  flowing in it. Hydrogen gas is collected in the tank that had been  connected   to  the  intake   manifold   of  the mixing unit to mix with oxygen.

These functions are happening in a unit named as “Hydrocell”  that  has  been  developed  since  three years ago [4]. In figure 2 shows the hydrogen  gas production   equipment   used  for  experiments   on diesel engine.

  Figure 2. Apparatus of  hydrogen generator for 25 KVA genset