done it before
Belgium Netherlands stay united as a Nation state.
After some riots and unrest in Brussels August 1830. The Capital and government residence will be Brussels and not Amsterdam and the Hague.
Representation is by population. Which gives the province of Flanders and Brabant more seats, which in turn is the shift of power to the South, as desired by the ''Belgians''.
Language is not a problem it is still 19th century and almost every were in Europe the upper class speaks French.
(the language trouble of OTL Belgium is a result of suppression of the Dutch/Flemish during the 19th and most of the 20th century)
There are some issues over language but this is more related by fear of the Southern upper class, to lose there influence and power over the common people. Since 1820 a ambitious education program started which intend to educate all children in the language of their area, which in Flanders, Brabant, Limburg and partly, Henegouwen is Dutch.
There are large coal deposits some iron deposits which are increasingly exploited. The weavers and entrepreneurs of Ghent and Aalst are coping weaving and spinning techniques from the United Kingdom with much success. The port of Antwerp is booming, handling more freight than Amsterdam and Rotterdam together, Flushing benefit as well of the increased activities of Antwerp.
There are trading post scattered around the Indonesian archipelago, which are grated by Great Britain as a sphere of influence to the Netherlands. Trade post are as well around the African West coast. And a colony around the Suriname river.
Any thoughts of how this country can develop during the 19th century?
With the upcoming industry combined with potential large colonies and a reasonable sized population, it could develop as one of the larges industrial nations of Europe.
How would it develop as colonial power, will it be part in the scramble for Africa?
Would it be part of the Crimean war, the Prussian Danish war, or the Bruder krieg between Prussia and Austria?
Or would it try to develop its own splendid isolation?